The legal challenge claims that federal health officials are trying to coerce Florida into expanding subsidized healthcare insurance by threatening to end the so-called Low Income Pool, a $2.2 billion federal-state program that reimburses hospitals for uncompensated care.

Scott, a Republican who opposes Medicaid expansion, has said the two issues should be kept separate.

"I am glad Kansas and Texas are joining our fight against the Obama administration for attempting to coerce Florida into Obamacare expansion by ending an existing federal healthcare program and telling us to expand Medicaid instead," Scott said in a statement. "The U.S. Supreme Court has already called this sort of coercion tactic illegal."

The U.S. Centers for Medicare and Medicaid Services has declined to comment directly on the lawsuit. But in a statement last week, the agency said it would "work with Florida and each state that has an uncompensated care pool regardless of its Medicaid expansion status, to support access to healthcare for low-income residents that works for individuals, hospitals and taxpayers."

That Kansas Gov. Sam Brownback and Texas Gov. Greg Abbott joined the suit Monday is no coincidence. Both are Republicans in states that have rejected Medicaid expansion.

Like Florida, Kansas and Texas are also bracing for the end of a federal program that provides supplemental funding for hospitals. The Texas program runs through September 2016, according to Kaiser Health News. The program in Kansas ends in 2017.

The situation in Florida is more immediate. The LIP program is scheduled to end June 30, under an existing agreement with the federal government. State healthcare officials are hoping CMS will approve a proposed successor program, but no deal has been reached.

Last month, Acting CMS Director Vikki Wachino wrote a letter to Florida's top Medicaid official saying the future of the LIP program would be tied to whether Florida expands Medicaid, because the two pots of money would cover many of the same people. The letter infuriated Scott, who announced his plans to take legal action.

Abbott was quick to commend Scott's suit.

"Florida's approach should be determined by Floridians, not coerced by federal bureaucrats," he said, adding that Medicaid expansion was also bad for Texas.

Brownback echoed the sentiment Monday.

"In joining with Florida and Texas, Kansas is protecting the states' right to make their own determinations about these issues," he said.

Uncertainty over the LIP program and a philosophical diagreement over Medicaid expansion brought the 2015 legislation session to a crashing halt last week. Lawmakers will have to return to Tallahassee to pass a balanced budget before June 30. But there remains no resolution on either issue.

Gov. Gavin Newsom and Mayor Bill de Blasio initiated ambitious plans this week to cover drastically more residents, including undocumented immigrants who are not currently eligible for subsidized insurance.

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